Impact of Adenosine Analogue, Adenosine-5 ′ -N-Ethyluronamide (NECA), on Insulin Signaling in Skeletal Muscle Cells

Materials and Methods Rat L6 skeletal muscle cells were cultured in 25 cm 2 flasks. These differentiated cells were treated, and then, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) (probe-based) was used to measure the relative mRNA expression level for metabolic, inflammatory, and nuclear receptor genes including peroxisome proliferator-activated receptor gamma (PGC-1 α ), carnitine palmitoyl transferase 1 beta (CPT1B), long-chain acyl-CoA de hydrogenase (LCAD), acetyl-CoA carboxylase beta (ACC β ), pyruvate dehydrogenase kinase 4 (PDK4), hexokinase II (HKII), phosphofructokinase (PFK), interleukin-6 (IL-6), and nuclear receptor subfamily 4, group A (NR4A) at different treatment conditions.Results Adenosine-5′-N-ethyluronamide (NECA), a stable adenosine analogue, significantly stimulate inflammatory mediator (IL-6) ( p < 0.001) and nuclear receptors (NR4A) ( p < 0.05) and significantly modulate metabolic (PFK, LCAD, PGC-1 α , and CPT1B) gene expressions in skeletal muscle cells ( p < 0.05, p < 0.05, p < 0.001, and p < 0.01, respectively). This present study shows that there is a noteworthy crosstalk between NECA and insulin at various metabolic levels including glycolysis (HKII), fatty acid oxidation (ACC β ), and insulin sensitivity (PDK4).Conclusions A novel crosstalk between adenosine analogue and insulin has been demonstrated for the first time; evidence has been gathered in vitro for the effects of NECA and insulin treatment on intracellular signaling pathways, in particular glycolysis and insulin sensitivity in skeletal muscle cells.